Various types of probes have found applications in chemical sensing, electronics testing, and medicine. Medical applications raise particularly challenging demands on a probe to be used for sensing or stimulation. For example, probes intended for use in interfacing directly to human tissue present several conflicting requirements. On one hand, it is desirable that a probe be quite rigid and strong so that it can be pushed through human tissue without breaking or deforming. On the other hand, it is desirable that a probe be very small, to minimize tissue damage, and flexible, so that is can move with the tissue into which it is embedded to avoid tearing.
In general, placement of probes into human tissue, such as the brain or a nerve has required a skilled surgeon to carefully position electrodes one by one at desired locations. This process is difficult and time consuming, and mistakes can lead to injury to the subject. Single probes are also difficult to fix in position without causing injury.
Probe arrays are known which provide for multiple connection points. Typically, these probe arrays are manufactured using silicon planar technology. The resulting arrays suffer from several drawbacks. The individual probe elements are brittle and relatively large compared to the size of nerve endings. Additionally, known probe arrays have relatively widely spaced probe tips, providing lower spatial resolution than desired.